Cognos 8.4 and TM1 9.5

I have been meaning to write about my experiences and learning of writing Cognos Reports (version 8.4) over TM1 cube since long. Finally got around doing it today. In coming days, I will keep on adding new points that I learn and are worth mentioning.

The most irritating and strange behaviour we saw during this development is – many standard OLAP reporting features of Cognos stop working after you put rules in the TM1 cube. These features are:

1. Automatic Aggregation: All the measure with aggregation set to automatic stop working and you have to define the aggregation function. i.e. Total in most cases.

2. Slicer and Row Member sharing: Often you put many slicers in query each based on a prompt. So you might have slicers on Dates, Products, Location, Currency, Scaling, etc. These will be standard in all reports with standard prompts and irrespective of what dimensions you have in crosstab report. However, after putting rules in TM1 cube, if we have a dimension in rows or columns (say Products) and also have a slicer on the same dimension, report stopped showing numbers!

3. Multi Select in slicers: If we choose multiple members or set in slicer, the report won’t show numbers


This phenomena is also seen in Analysis Studio and affected power user reporting!

These are very irritating issues and as we had to use the cube rules, we changed our reports to get around above limitations. These changes were:

1. Define aggregation and rollup aggregation for all measures. Anyway this is one of the best practices, so no complains.

2. Ensure that dimensions used in rows and columns don’t appear in slicer. So, if you have PRODUCTS on rows and DATES on columns, don’t use them in slicer. This was tricky as we change the row and column members dynamically based on user choice [i.e. user can choose whether they want to see the data by Dates, Area, Products, or other dimension] and it we had to dynamically change the slicers accordingly using macro etc.

3. Wherever we had to allow multi-choice for prompts, instead of put them in slicer, we define TOTAL WITHIN SET calculation and used it on rows!

While writing this post, I have no idea why Cognos reports started not supporting the above mentioned features and even the Analysis Studio! But it has been raised to IBM and we are waiting to hear back from them..